Process for the production of colored pictures, particularly in natural colors on paper, films, and the like



7, 193%. ERG 29@36945 CULARLY F. L] PROCESS FOR THE PRODUCTION OFCOLORED PICTURES PAR'II IN NATURAL COLORS ON PAPER, FILMS AND THE LIKEFiled March 15, 1934 Patented Apr. 7, 1936 PATENT OFFICE PROCESS FOR THEPRODUCTION OF COL- ORED PICTURES, PARTICULARLY IN NAT- UEAL COLORS THELIKE N PAPER, FILMS, AND

Friedrich Lierg, Vienna, Austria Application March 15, 1934, Serial No.715,718 In Austria October 15, 1932 1 Claim. (c1. 101-149 This inventionrelates to a process for-the production of colored pictures particularlyin natural colors'on paper, films and the like whereby colloid printingimages produced by tanning in a picture-like manner or colloid reliefimages are soaked with a metallic salt solution yielding together withthe electrolyte the color precipitate. The present invention has for itsobject the improvement of. this process by carrying it out in anexpeditious manner. It is already known to embody the reagent, yieldingtogether with the electrolyte the color precipitate, into the printingsurface in a water insoluble condition or in a state which can beremovedby water with great difliculty only. In view thereof, the

1 application of precipitating solutions after the printing is dispensedwith, an image of perfect sharpness and shading being formed during theprinting, because the electrolyte hasno oppor- 2 tunity to spread overthe printing layer. Consequently it is not necessary to washaway aprecipitating liquid and remove the adhering liquid.-

The paper or the film can be preliminarily moistoned for the whole printand provided with the 25 color image is removed from the printingdevice. Care has to be taken that an excess of a solution of theelectrolyte yielding color precipitates'does not adhere to "the printingmatrices if they contactwith the printing layer, seeing tion. Thereforebefore the printing it is necessary 35 to remove the adhering solutionfrom the matrix. Thepresent invention makes use of the.

characteristic that electrolytic solutions readily pass from colloidallayers and essentially consists in that before the printing the printingmatrix 40 is placed into contact with a moist colloidal substance inwhich the electrolyte yielding color precipitates is embodied.

The invention can be carried out in different ways, an arrangement forcarrying out the pres- 45 ent process for three color printing beingshown diagrammatically and by wayof example in the accompanying drawing.

The colloid from which the electrolyte yielding color precipitatespasses to the printing ma- 50 trix may be applied; for instance, in athin layer to a preferably flexible base, for instance to a celluloidband, and alternately is led through the electrolyte solution andpressed onto the print ing film. Before this compression it is ofadvantage to remove the adhering excess of the that the electrolyte isapplied'to the printing mat solution although it may be possible topress out any excess of the solution by this compression. Still theborders of the printing matrices may contain some excess of thesolution. The excess is removed from the colloid layer preferably by 5rubber wipers, rollers or the like. There is no danger that the colloidlayer is damaged thereby, because, contrary to the printing matrix, thecolloid layer forms an uninterrupted surface.

Anyresidue of the liquid can -be removed by m wiping rollers made oflinen or the like or provided with a. finely, porous but non-colloidalsurface. It has been found that the degree of concentration of colloidallayers, imbibed with electrolytic solutions of a certain degree ofconcentration, is not varied by contact with absorbent layers ofnon-colloidal characteristic. In this respect for instance filter paperpossesses a certain colloidal characteristic which is noticeable in thatthe degree of concentration of the electrolytic w imbibition is variedin the colloidal layers. Washed out fabrics do not show this effect.Therefore it forms a part of this invention to remove an excess ofadhering solution from colloidal layers, which are utilized fortransferring the electrolyte yielding color precipitates to the printingmatrix, by means of finely porous faces of a noncolloidal characteristic(terra-cotta, textile fabrics, metal fabrics, rubber sponge or thelike). of course also the printing matrix can be treated with materialsof this kind, for instance by textile fabric rollers which do not go the1 fine characteristics.

In order to dispense with any means for removing the adhering liquidsuch as wipers, roll- 5 ers and the like it is proposed by the inventorto use a gelatinous colloidal mass containing the correspondingelectrolyte and, besides the hardening agent (for instance chrome alum),also a moistening agent (forinstance glycerine).

When in contact with the printing matrix, the electrolyte yielding colorprecipitates passes from.

a colloidal mass of i this kind into said matrix until a state ofequilibrium is reached. The electrolyte, withdrawn from the surface ofthe colloid, is uninterruptedly replaced from the interior of the mass.In case of a sufl'icient thickness of the colloidal layer, theconcentration of the electrolyte is noticeably reduced only after a veryconsiderable number of prints.

Further the withdrawn electrolyte can. be replaced from the backside.For this object it is not necessary that the colloidal surface is of anyconsiderable thickness. The colloidal surface is applied for instance toa surface or a cylinder of porous clay or the like. The backside of thesurface is in contact with the electrolytic solution or the cylinder isfilled with the latter. This solution diiiuses through the porous walland always maintains the colloidal layer on the same degree ofconcentration of the electrolyte. The electrolytic solution can besubjected to pressure in order to effect a fast diffusion through theporous wall.

In the illustrated arrangement for a method of expeditiously printing inthree colors by means of electrolytic solutions, are employed endlessfilm bands which carry the printing matrices in the shape of gelatinouswash-out reliefs. In the illustrated example, the printing, paper or theprinting film is coated by a colloidal layer, containing a ferric salt,lead bromide and dimethylglyoxime as precipitating agent.

Rollers for leading and guiding the printing paper and the matrix filmare arranged in a frame I. The printing paper I is wound oil. of aroller 3 and passes by way of rollers 4 through a water bath 5, and isled between rubber wipers 6 and pairs of wiping rollers l to a pair ofrollers 8 and 9 for starting the proper printing process. The firstprinting arrangement for carrying out the blue print consists of anendless band l which is in the form either of a thin flexible metal tapecarrying the individual printing matrices or of a celluloid band which,if desired, is provided directly with the washed relief. The

band ill moves over rollers ll, l2, l3 and I4 and around the drum 15. Anendless celluloid band l8. which is coated with a colloid layer on itsoutside and passes over a roller l1, moves between the drum l and theband Ill, whereby the printing matrices face the drum IS. The roller llpartly dips into a trough l8, containing a solution of potassiumferrocyanide. The excess of solution is removed by rubber wipers l8 orporous rollers 20. During the movement over the drum ii, the solutionpasses from the band "5 to the printing matrices of the band I, whichthus are permanently provided with the electrolyte yielding colorprecipitates up to a certain degree of concentration. The printing paper2 is pressed onto the matrix band l0 between the rollers II and 2| andnow both the printing paper 2 and the band l0 remain in contact untilthe rollers I! and 22 are reached. During contact the solution ofpotassium ferrocyanide embodied in the relief of the printing matrix I0passes into the printing paper 2 and forms the blue partimage in theform of Prussian blue. Theblue part-image is the most important for thecharacteristic of the image and therefore here the absorption of theelectrolyte from the solution is the most satisfactory, because byvarying the concentration of the solution it is possible to readilychange the force of the blue print. The yellow print matrices, arrangedon the band l0 are imbibed with potassium monochromate for carrying outthe yellow print now carried out.

For this object, a band l0 passes round rollers II l2 l3 I4 and a drum[5' the latter being coated with a thick layer 23' of a gelatinoussubstance containing the potassium monochromate. Thelatter is a veryeasily soluble salt and therefore a quantity suificient for-a longperiod of' printing is applied; very small quantities thereof passing tothe printing matrices at a time. The printing paper 2, coming from therollers l2 and 22, is pressed onto the band l0 between the.

rollers l I and 21' and is separated from the said .band on leaving therollers l2 and 22. Now

the printing paper 2 passes between the rollers II" l2" and is pressedonto the band Ill carrying the red print matrices, which are imbibedwith a nickel salt. In this case the drum I5" is' in the form of ahollow cylinder'of porous clay or the like, which is permanently filledwith a solution of nickel salt. The outside of the clay a red image ofnickel dimethylglyoxime in the layer of the paper. Finally the paperband I is wound up on a roller 20. The printing devices are driven by acommon shaft 24 by means of worm wheel gears. Each worm 25 is separatelyadjustable on the shaft 24 in order to adjust the bands l0, l0 III" forcoinciding exactly with the images on the printing band 2. For printingfilm bands for cinematographic reprorices, together with thedimethylglyoxime forms duction, printing matrices films of a lengthcorresponding to the length of the film band to be produced aresubstituted for the endless bands I0 l0 it". Of course one oftheprinting devices can be used for printing pictures in a single color.

What I claim is:--

In a process for the production of colored pictures particularly innatural colors on the col? loidal printing surface of papers, films andthe like containing reagents which with electrolytes yield coloredprecipitates in a water insoluble condition and in which colloidprinting matrices produced by tanning in a picture-like'manner areimbibed with an electrolyte solution able to yield a color precipitatewith said reagents, placing into contact said matrices with saidcolloidal printing surface to produce the precipitate in a picture-likemanner, and separating said matrices from said printing surface, thestep of providing said printing matrices with a colloidal surface soakedwith said electrolytic solution before placing incontact said matriceswith said printing surface.

FRIEDRICH IJERG.

